Effect of butanol fraction from Cassia tora L. seeds on glycemic control and insulin secretion in diabetic rats

Cassia tora L. seeds have previously been reported to reduce blood glucose level in human and animals with diabetes. In the present study, the effects of Cassia tora L. seed butanol fraction (CATO) were studied on postprandial glucose control and insulin secretion from the pancreas of the normal and diabetic rats. Diabetes was induced by an i.p. injection of Streptozotocin (55 mg/kg BW) into the male Sprague-Dawley rats. The postprandial glucose control was monitored during a 240 min-period using a maltose loading test. In normal rats, rats fed CATO (20 mg/100 g BW/d) showed lower postprandial glucose levels in all the levels from 30 min up to 180 min than those in the control rats without CATO (p<0.05). In diabetic rats, those levels in the CATO group seemed to be lower during the 30~180 min, but only glucose level at 30 min showed significant difference compared to that in the control group. Moreover, CATO delayed the peak time of the glucose rise in both normal and diabetic rats in the glucose curves. On the other hand, when CATO was administered orally to the diabetic rats for 5 days, 12 hr fasting serum glucose level was decreased in the diabetic rats (p<0.05). Degree of a decrease in 12 hr fasting serum insulin levels was significantly less in the diabetic CATO rats as compared to diabetic control rats. On the last day of feeding, beta cells of the pancreas were stimulated by 200 mg/dL glucose through a 40 min-pancreas perfusion. Amounts of the insulin secreted from the pancreas during the first phase (11~20 min) and the second phase (21~40 min) in the CATO fed diabetic rats were significantly greater than those in the diabetic control group (p<0.05). These findings indicated that constituents of Cassia tora L. seeds have beneficial effect on postprandial blood glucose control which may be partially mediated by stimulated insulin secretion from the pancreas of the diabetic rats.

Reproducibility of VPCT parameters in the normal pancreas: comparison of two different kinetic calculation models

RATIONALE AND OBJECTIVES

To assess the reproducibility of volume computed tomographic perfusion (VPCT) measurements in normal pancreatic tissue using two different kinetic perfusion calculation models at three different time points.

MATERIALS AND METHODS

Institutional ethical board approval was obtained for retrospective analysis of pancreas perfusion data sets generated by our prospective study for liver response monitoring to local therapy in patients experiencing unresectable hepatocellular carcinoma, which was approved by the institutional review board. VPCT of the entire pancreas was performed in 41 patients (mean age, 64.8 years) using 26 consecutive volume measurements and intravenous injection of 50 mL of iodinated contrast at a flow rate of 5 mL/s. Blood volume(BV) and blood flow (BF) were calculated using two mathematical methods: maximum slope + Patlak analysis versus deconvolution method. Pancreas perfusion was calculated using two volume of interests. Median interval between the first and the second VPCT was 2 days and between the second and the third VPCT 82 days. Variability was assessed with within-patient coefficients of variation (CVs) and Bland-Altman analyses. Interobserver agreement for all perfusion parameters was calculated using intraclass correlation coefficients (ICCs).

RESULTS

BF and BV values varied widely by method of analysis as did within-patient CVs for BF and BV at the second versus the first VPCT by 22.4%/50.4% (method 1) and 24.6%/24.0% (method 2) measured in the pancreatic head and 18.4%/62.6% (method 1) and 23.8%/28.1% (method 2) measured in the pancreatic corpus and at the third versus the first VPCT by 21.7%/61.8% (method 1) and 25.7%/34.5% (method 2) measured also in the pancreatic head and 19.1%/66.1% (method 1) and 22.0%/31.8% (method 2) measured in the pancreatic corpus, respectively. Interobserver agreement measured with ICC shows fair-to-good reproducibility.

CONCLUSIONS

VPCT performed with the presented examinational protocol is reproducible and can be used for monitoring purposes. Best reproducibility was obtained with both methods for BF and with method 2 also for BV data for both follow-up studies.

Ex situ Perfusion of Pancreas for Whole-Organ Transplantation: Is it Safe and Feasible? A Systematic Review

INTRODUCTION

Pancreas transplantation is currently one of the best treatments proposed in highly selected patients with unstable and brittle type 1 diabetes. The objective of pancreas transplantation is to restore normoglycemia and avoid the occurrence of complications associated with diabetes. Graft pancreatitis and thrombosis, arising from ischemia reperfusion injuries, are major causes of graft loss in the postoperative period. Ex situ perfusion, in hypothermic or normothermic settings, allowed to improve ischemic reperfusion injury in other organ transplantations (kidney, liver, or lung). The development of pancreatic graft perfusion techniques would limit these ischemic reperfusion injuries.

OBJECTIVE

Evaluation of the safety and feasibility of ex situ perfusion of pancreas for whole-organ transplantation.

METHODS

English literature about pancreas perfusion was analyzed using electronic database Medline via PubMed (1950-2018). Exclusion criteria were studies that did not specify the technical aspects of machine perfusion and studies focused only on pancreas perfusion for islet isolation.

RESULTS

Hypothermic machine perfusion for pancreas preservation has been evaluated in nine studies and normothermic machine perfusion in ten studies. We evaluated machine perfusion model, types of experimental model, anatomy, perfusion parameters, flushing and perfusion solution, length of perfusion, and comparison between static cold storage and perfusion.

CONCLUSIONS

This review compared ex vivo machine perfusion of experimental pancreas for whole-organ transplantation. Pancreas perfusion is feasible and could be a helpful tool to evaluate pancreas prior to transplantation. Pancreas perfusion (in hypothermic or normothermic settings) could reduce ischemic reperfusion injuries, and maybe could avoid pancreas thrombosis and reduce morbidity of pancreas transplantation.

Pterostilbene Fails to Rescue Insulin Secretion and Sensitivity in Multiple Murine Models of Diabetes

Diabetes incidence is rising globally at an accelerating rate causing issues at both the individual and societal levels. However, partly inspired by Ayurvedic medicine, a naturally occurring compound called pterostilbene has been demonstrated to protect against diabetes symptoms, though mainly in rats. The purpose of this study was to investigate the putative protective effect of pterostilbene on the two main aspects of diabetes, namely insulin resistance and decreased insulin secretion, in mice. To accomplish this, we employed diet-induced obese as well as streptozotocin-induced diabetic C57BL/6NTac mice for fasting glucose homeostasis assessment, tolerance tests and pancreas perfusions. In addition, we used the polygenic model of diabetes TALLYHO/JngJ to assess for prevention of β-cell burnout. We found that the diet-induced obese C57BL/6NTac mice were insulin resistant, but that pterostilbene had no impact on this or on overall glucose regulation. We further found that the reported protective effect of pterostilbene against streptozotocin-induced diabetes was absent in C57BL/6NTac mice, despite a promising pilot experiment. Lastly, we observed that pterostilbene does not prevent or delay onset of β-cell burnout in TALLYHO/JngJ mice. In conjunction with the literature, our findings suggest variations in the response to pterostilbene between species or between strains of species.